I recommend IC Markets and TopFX. I have used them both for over four years without any issues (trading, depositing, withdrawing, etc.).
Both have excellent support and both support my favourite trading platform – cTrader.
However, it’s worth noting that the minimum lot size for indices at IC Markets is 1 lot.
With TopFX, it’s 0.01 lots, so you can trade with a much smaller account ($100 or less).